Over 90% of the 184,000 women diagnosed with breast cancer in 2000 will undergo surgery as part of their curative treatment. Despite improvements in pharmacological management, surgical procedures under general anesthesia continue to be associated with clinically significant side effects, chief among which are pain and nausea. These clinical problems are particularly severe following surgical treatment for breast cancer and can require additional pharmacologic intervention, prolong recovery room stay, delay discharge, and lead to unanticipated readmission. Clinical research with other surgical populations has indicated that hypnosis can reduce intraoperative complications, reduce postoperative symptoms and enhance recovery (e.g., reduce pain, nausea, hospital stays), however, the treatment efficacy of hypnotic techniques with breast cancer surgical patients has yet to be established. A separate line of previous clinical research with surgery populations has indicated that preoperative psychological factors (emotional distress and cognitive expectations) are predictive of patients' postoperative experiences of side effects, but again research on breast cancer surgical patients is scant. The proposed research will bridge the two previous lines of research by combining a randomized clinical trial, (in which the effects of a preoperative hypnosis intervention to control side effects are compared to attention control), with a prospective quasi-naturalistic study, (in which the relations between preoperative psychological factors and patients' reactions to surgery are examined). In addition to establishing the applicability to breast cancer patients of findings in the general psychological, hypnosis and surgical literatures, the goal of proposed study is to make novel theoretical contribution by examining the potential role of psychological factors as the "active ingredients" in the beneficial effects of hypnosis. The proposed study will also make a novel practical contribution by examining cost-effectiveness of the hypnosis intervention, an approach which may have compelling implications for clinical practice as well as future behavioral research. The Specific Aims of the study are: 1) To investigate the impact of a presurgical hypnosis intervention on women scheduled for surgical treatment for breast cancer; 2) To investigate the contribution of preoperative emotional distress, and cognitive expectations to post- surgery side effects and recovery; 3) To determine whether the beneficial effects of the hypnosis intervention are accounted for (mediated) by differences in presurgery cognitive expectations and emotional distress; and 4) To investigate the cost-effectiveness of the presurgical hypnosis invention. o achieve these aims, 140 breast cancer patients scheduled for mastectomy will be randomly assigned to a hypnosis intervention group or an attention control group. The impact of the hypnosis intervention on postoperative nausea, pain, recovery from surgery, and cost- effectiveness will be analyzed within an experimental study design. The influence of presurgery distress and expectations of side effects will be analyzed within quasi-naturalistic study designs. The possible mediational role of these factors in hypnosis effects will be examined will classic statistical approaches.